Last Men Standing: Chlamydatus Portraits and Public Life in Late Antique Corinth

Notable among the marble sculptures excavated at Corinth are seven portraits of men wearing the long chlamys of Late Antique imperial office. This unusual costume, contemporary portrait heads, and inscribed statue bases all help confirm that new public statuary was created and erected at Corinth during the 4th and 5th centuries. These chlamydatus portraits, published together here for the first time, are likely to represent the Governor of Achaia in his capital city, in the company of local benefactors. Among the last works of the ancient sculptural tradition, they form a valuable source of information on public life in Late Antique Corinth

The Sail-Backed Reptile Ctenosauriscus from the Latest Early Triassic of Germany and the Timing and Biogeography of the Early Archosaur Radiation

Background Archosaurs (birds, crocodilians and their extinct relatives including dinosaurs) dominated Mesozoic continental ecosystems from the Late Triassic onwards, and still form a major component of modern ecosystems (>10,000 species). The earliest diverse archosaur faunal assemblages are known from the Middle Triassic (c. 244 Ma), implying that the archosaur radiation began in the Early Triassic (252.3–247.2 Ma). Understanding of this radiation is currently limited by the poor early fossil record of the group in terms of skeletal remains. Methodology/Principal Findings We redescribe the anatomy and stratigraphic position of the type specimen of Ctenosauriscus koeneni (Huene), a sail-backed reptile from the Early Triassic (late Olenekian) Solling Formation of northern Germany that potentially represents the oldest known archosaur. We critically discuss previous biomechanical work on the ‘sail’ of Ctenosauriscus, which is formed by a series of elongated neural spines. In addition, we describe Ctenosauriscus-like postcranial material from the earliest Middle Triassic (early Anisian) Röt Formation of Waldhaus, southwestern Germany. Finally, we review the spatial and temporal distribution of the earliest archosaur fossils and their implications for understanding the dynamics of the archosaur radiation. Conclusions/Significance Comprehensive numerical phylogenetic analyses demonstrate that both Ctenosauriscus and the Waldhaus taxon are members of a monophyletic grouping of poposauroid archosaurs, Ctenosauriscidae, characterised by greatly elongated neural spines in the posterior cervical to anterior caudal vertebrae. The earliest archosaurs, including Ctenosauriscus, appear in the body fossil record just prior to the Olenekian/Anisian boundary (c. 248 Ma), less than 5 million years after the Permian–Triassic mass extinction. These earliest archosaur assemblages are dominated by ctenosauriscids, which were broadly distributed across northern Pangea and which appear to have been the first global radiation of archosaurs

Sedimentological and Rheological Properties of the Water–Solid Bed Interface in the Weser and Ems Estuaries, North Sea, Germany: Implications for Fluid Mud Classification

Fine, cohesive sediment suspensions are a common feature of estuarine environments. Generally, multilayer models are used to describe the vertical distribution of such sediments. Such conceptional models normally distinguish at least high suspended sediment concentrations (SSCs) as a topmost layer and a consolidated bed layer, often including an intermediate, fluid mud layer. Rheological, and in particular sedimentological properties are rarely included in these models. New data from two different estuaries provide new insights that can contribute toward the classification of nearbed cohesive sediments. The water–solid bed interfaces within the turbidity maximum zones of the Weser and Ems estuaries were sampled with 2–4-m-long cores. At 10-cm intervals, values of SSC, viscosity, particulate organic matter, mud: sand ratio, temperature, salinity, and grain-size distributions were determined. By normalizing these parameters to SSC and performing a cluster analysis, sediment suspensions of <20 g/L SSC, fluid mud with up to 500 g/L SSC, and an underlying cohesive/consolidated bed can each clearly be distinguished. However, changes in flow behaviour and sedimentological characteristics represented by a shift in the cluster grouping support a subdivision of the fluid mud into a low-viscosity (I) (20–200 g/L SSC) and a high-viscosity (II) (200–500 g/L SSC) layer. Furthermore, by normalizing SSC measurements, site-specific differences were observed in the rheological behaviour of the fluid mud which might be caused by differences in grain-size composition. This suggests that the widely accepted 3-layer model of vertical SSC profiles should be extended by two layers of fluid mud identified in this study

Sedimentary dynamics on isolated highs in Lake Baikal: evidence from detailed high-resolution geophysical data and sediment cores

High- and very-high-resolution seismic data, side-scan sonar mosaics and piston cores from three isolated highs in Lake Baikal (Vydrino Shoulder, Posolsky Bank, Continent Ridge) have allowed to document in unprecedented detail the depositional, re-depositional and tectonic processes and to characterise the overall sedimentary environment on such isolated highs. Our data show that Vydrino Shoulder actually represents a turbidity- or underflow-sourced slope fan, with a distinct channel-levee morphology, and affected by tectonics and stratigraphic unconformities. Sediment cores contain up to 90% of terrigenous material. Posolsky Bank is a major tilted fault block, clearly affected by tectonic activity, by stratigraphic unconformities and by mass wasting along its margins. Sedimentation on its crest is undisturbed, but average sedimentation rates are high due to the influence of the nearby Selenga River. Continent Ridge is also affected by active faulting, stratigraphic unconformities and by mass-wasting along its flanks. The area receives only 30% of terrigenous input. There are no signs of sediment reworking due to bottom-currents. Our study thus shows that in comparison with other environments in Lake Baikal, the isolated highs probably hold the best potential to contain a high-quality, continuous, undisturbed and undiluted sedimentary record suitable for paleoclimate research. (C) 2004 Elsevier B.V. All rights reserved.Continen

Depth limits of Bermudan scleractinian corals: A submersible survey

Depth distribution, zonation pattern and growth morphology of 17 hermatypic and 4 ahermatypic coral species were investigated at eight different locations along the Bermuda platform with the research submersible GEO and by SCUBA diving in August–September 1983. Hermatypic coral growth occurs to a depth of 50 to 70 m, with a single Montastrea cavernosa growing at 78 m. Dominant forms in shallow-water coral communities are Diploria sp. and Porites astreoides, while M. cavernosa, Agaricia fragilis and Scolymia cubensis occur in deep-water associations below 60 m. Vertical visibilities (up to 178 m) and distribution of the photosynthetically active radiation revealed good light penetration values (1% level at about 100 m depth), which should favour hermatypic coral growth to a much greater depth than it actually occurs. Nor should the prevailing temperatures limit the depth of coral growth. Most deep-water hermatypes observed grow on remnants of Pleistocene reefs down to about 60 m. The vast areas of large massed rhodolith nodules below 50 to 60 m are unsuitable bottom for coral colonisation. Macroalgae growth seems to be the strongest factor controlling coral growth in deep water. Bermuda stony corals have a low growth form diversity. Various intraspecific morphs may occur at the same as well as at different depths, with a general trend towards flatter shapes with depth. Comparison with a similar study on Red Sea corals suggests that annual distribution of radiant energy on the most northern Atlantic reefs of Bermuda may be responsible for the occurrence of flat and cuplike growth forms in relatively shallow water, and for the shallower depth limits of hermatypic growth

Fazies-Analyse im Paläozoikum des Oslo-Gebietes

Alle vorhandenen bathymetrischen Kriterien (Lithologie, Sedimentstrukturen aller Art, Fossilorientierung, Stromrichtungen, benthonische Fauna und fossile Lebensspuren) werden zur Rekonstruktion der Sedimentationsgeschichte und der Krustenbewegungen für das Kambrium, Ordovizium und Silur im Oslo-Gebiet herangezogen. Zwei Beckenbildungs- und Krustensenkungszeiten können nachgewiesen werden. Sie sind durch eine Episode des Stillstandes oder der Aufwärtsbewegung der Kruste voneinander getrennt. Das zeigt sich durch Ablagerung flachmeerischer und z. T. konglomeratischer Sedimente am Ausgang des Ordoviziums deutlich an.All available bathymetric criteria (lithology, sedimentary structures, fossil orientation, current features benthos, and trace fossils) are used to reconstruct the sedimentary history and the crustal movements of the Oslo district during Cambrian, Ordovician, and Silurian times. Two phases of basin development and crustal subsidence are recognized, separated by an episode of crustal rest or uplift that resulted in the deposition of shallow marine and conglomeratic sediments at the close of Ordovician times.Tous les critères bathymétriques (lithologie, structures sédimentaires, orientation de fossiles, courants, faunes benthiques et traces fossiles) sont analysés pour reconstituer l'histoire sédimentaire et les mouvements de l'écorce terrestre pendant le Cambrien, l'Ordovicien et le Silurien dans la région d'Oslo. On peut mettre en évidence deux phases d'affaissement qui sont séparées par un épisode d'arrêt ou de soulèvement du fond, caractérisé par lépôt de sédiments néritiques et de conglomérats à la fin de l'Ordovicien.Фациальный анализ по леозойских отложени й (кембрийская, ордови к ская и силурийская систем ы) в окрестностях Осл о (Норвегия) проводился по следующим критери ям: литология, структу ры осадков, ориентировка окаменелостей, напра вление, бентонные орг анизмы и следы их жизнедеятел ьности. В образовании геосин клинали отмечается д ва периода